Dilshan R Jayakody’s Web Log

RDS ( Radio Data System ) is a communication protocol standard used for embedding small amounts of digital information in traditional FM radio broadcasts. It enables radio stations to transmit data such as station identification, program information, and traffic updates.  To capture and decode RDS data, one method involves using a Software Defined Radio (SDR) along with GNU Radio and RFtap . GNU Radio provides a framework for creating software radios, while RFtap acts as a bridge between GNU Radio and conventional network monitoring and packet analysis tools like Wireshark . Decoding RDS data using Wireshark. Unfortunately, as of the time of writing, RFtap is no longer being maintained and does not work with the latest version of GNU Radio (version 3.10.10). This post offers guidelines for rebuild and using RFtap with the new GNU Radio release. This post assumes that the reader has access to DVB-T dongles based on the Realtek RTL2832U and a PC running Ubuntu or Debian Linux. For ...

Recently I got an interest to experiment with NOAA weather satellite reception techniques. As a first thing, I did search on the internet for a suitable antenna for NOAA satellite frequencies (137.100 MHz - 137.9125 MHz). After examining a couple of designs, I decided to build a Turnstile antenna which is designed by Ivo Brugnera I6IBE . Due to the COVID19 lock-down, I build this antenna using parts that are already available in my inventory. Originally, I build this antenna on a wood-stick, and later I changed it to a stable setup as shown below. Assembled antenna for 137 MHz NOAA weather satellite receptions. Following materials and components are used for the above construction: - Two 8cm × 8cm × 6cm waterproof ABS project box. - 54cm long, ⌀ 21mm PVC tube, which is reinforced by inserting water resistivity wood stick. - 8mm thread roads. - M8 nuts and M8 flat washers. - 50Ω and 75Ω coaxial cables. - PL259 male and female connectors. Before constructing this ant...